Process of grinding caustic soda



"UNITED STA";

" ATENT QFFICE.

FRANK P. HARNED, OF CAMDEN, NE? JERSEY, ASSIGNOR 'l O CLEMENT \VAINVRIGH'QISRAEL BL WAINVVRIGHT, AND JOSEPH R. \VAIN\VRIGHT,

ALL OF PHILADELPHIA, PENNSYLVANIA.

PROCESS OF GRINDING CAUSTIC SODA.

SPECIFICATION forming part ot Letters Patent No. 286,132, dated October 2, 1883.

Application filed October 30, 182. (No srecimens.)

T6 all whom it may concern.-

Be it known that I, FRANK P. HARNED, of Camden, in the county of Camden and State of New Jersey, have invented a certain new 5 and useful Improvement in the Process of Grinding or Coniminuting Caustic Soda, of which improvement the following is a specification.

The difliculty heretofore attending the prep- IQ arati on of granulated caustic soda for the market, which difi'ieulty has arisen from the rapid deliquescence ofthc soda upon exposure to the atmosphere, has led to the adoption of a process of grinding it hot or in heated .1 apparatus, or in a highly-heated atmosphere,

such process beingdescribed in Letters Patent of the United States N o. 243, 939; granted under dnteot' July 5, 4881, to \Villiam J. Menzies, assignor of onehalf interest to 20 George I. Lewis, in which patent reference is made to English Letters Patent No. 4,274, is sued under date of October 21, 1879. The use of heat in connection with such process is,

. however, expensive and :otherwise undesir- 2 able; and it is the object of my invention to simplify the process of grinding or comminutingcaustic soda at the ordinary temperature by counteracting and restraining the tendency of the soda to deliquesce during its necessary 0 exposure'to'the atmosphere; to which end my invention consists in the addition to the cans tic soda of dry soda-ash, or carbonate of soda, which will absorb the moisture attracted by the caustic soda and restrain its deliquescence.

5 I break up the mass of caustic soda or caustic alkali in the ordinary way, and as-it comes from the, breaker I throw over the broken mass a small quantity of dry soda-ash, 01"

carbonate of soda of good color and high test. I then feed this mixture of caustic soda or caustic alkali and soda "ash, or carbonate of soda, through a mill preferablytot' thekind known as adisintegrator, which comminutes or cduces it, and I then bolt the ground mixture in the usual manner. The quantity ot' the soda-ash or carbonate of soda requisite for the purpose will not exceed from one to two per cent. of the mass of caustic soda or caustic alkali, and I have found this quantity sufiicient to elt'ectuall y counteract and rest-rain the deliquescence of the caustic soda during peratures, which improvement consists in adding to the broken mass of caustic soda, carbonate of soda, or soda-ash, and grinding and bolting the mixture, substantially as and for the purpose described;

FRANK r. HARNEDQ Witnesses:

CHARLES F. 'ZIEG'LER,

WILLIAM W. FARR, Jr. 

